Summary statement: the Sygen(GM-1 ganglioside) clinical trial in acute spinal cord injury

Turning the spotlight on the oligosaccharide chain of GM1 ganglioside

It is well over a century that glycosphingolipids are matter of interest in different fields of research. The hydrophilic oligosaccharide and the lipid moiety, the ceramide, both or separately have been considered in different moments as the crucial portion of the molecule, responsible for the role played by the glycosphingolipids associated to the plasma-membranes or to any other subcellular fraction. Glycosphingolipids are a family of compounds characterized by thousands of structures differing in both the oligosaccharide and the ceramide moieties, but among them, the nervous system monosialylated glycosphingolipid GM1, belonging to the group of gangliosides, has gained particular attention by a multitude of Scientists. In recent years, a series of studies have been conducted on the functional roles played by the hydrophilic part of GM1, its oligosaccharide, that we have named “OligoGM1”. These studies allowed to shed new light on the mechanisms underlying the properties of GM1 defining the role of the OligoGM1 in determining precise interactions with membrane proteins instrumental for the neuronal functions, leaving to the ceramide the role of correctly positioning the GM1 in the membrane crucial for the oligosaccharide-protein interactions. In this review we aim to report the recent studies on the cascade of events modulated by OligoGM1, as the bioactive portion of GM1, to support neuronal differentiation and trophism together with preclinical studies on its potential to modify the progression of Parkinson’s disease.

A Review on the Etiology and Management of Pediatric Traumatic Spinal Cord Injuries

CONTEXT

Pediatric traumatic spinal cord injury (SCI) is an uncommon presentation in the emergency department. Severe injuries are associated with devastating outcomes and complications, resulting in high costs to both the society and the economic system.

EVIDENCE ACQUISITION

The data on pediatric traumatic spinal cord injuries has been narratively reviewed.

RESULTS

Pediatric SCI is a life-threatening emergency leading to serious outcomes and high mortality in children if not managed promptly. Pediatric SCI can impose many challenges to neurosurgeons and caregivers because of the lack of large studies with high evidence level and specific guidelines in terms of diagnosis, initial management and of in-hospital treatment options. Several novel potential treatment options for SCI have been developed and are currently under investigation. However, research studies into this field have been limited by the ethical and methodological challenges.

CONCLUSION

Future research is needed to investigate the safety and efficacy of the recent uprising neurodegenerative techniques in SCI population. Owing to the current limitations, there is a need to develop novel trial methodologies that can overcome the current methodological and ethical limitations.

Traumatic thoracic ASIA A examinations and potential for clinical trials

STUDY DESIGN

Retrospective review of prospective database.

OBJECTIVE

To define the variability of neurologic examination and recovery after nonpenetrating complete thoracic spinal cord injuries (American Spinal Injury Association [ASIA] A).

SUMMARY OF BACKGROUND DATA

Neurologic examinations after spinal cord injury (SCI) can be difficult and inconsistent. Unlike cervical SCI patients, alterations in thoracic (below T1) complete SCI (ASIA A-based on the ASIA Impairment Scale [AIS]) patients' examinations are based only on sensory testing, thus changes in the neurologic level (NL) are determined only by sensory changes.

METHODS

A retrospective review of the placebo control patients in a multicenter prospective database used for the pharmacologic trial of Sygen. Patients were included if they had a complete thoracic SCI on initial evaluation, with completed ASIA examinations at follow-up weeks 4, 8, 16, 26, and 52. Specifically, pin prick (PP) and light touch (LT) were assessed and the absolute change was calculated as the number of spinal levels at a given observation time.

RESULTS

Three thousand one hundred sixty-five patients were initially screened for the Sygen clinical trial, of which 51 were the control placebo patients used in this analysis. Alterations from the baseline examination (PP and LT) were fairly consistent and the median change/recovery in neurologic examination was 1 spinal level. Across all observations postbaseline, the average change for PP was 1.48 +/- 0.13 (mean +/- SE), and for LT, 1.40 +/- 0.13. There were equal proportions of directional changes (none, improved, lost).

CONCLUSION

Changes in a thoracic complete (ASIA A) SCI patients ASIA examination as measured through sensory methods (PP/LT) are fairly uncommon. The overall examination had only 1- to 2-level variability across patients, indicating minimal change in the sensory examination over the follow-up period. Stability in the ASIA examination as measured through sensory methods has thus been demonstrated over time, making it an excellent tool to monitor changes in neurologic function.

Experimental strategies to promote spinal cord regeneration--an integrative perspective

Detailed pathophysiological findings of secondary damage phenomena after spinal cord injury (SCI) as well as the identification of inhibitory and neurotrophic proteins have yielded a plethora of experimental therapeutic approaches. Main targets are (i) to minimize secondary damage progression (neuroprotection), (ii) to foster axon conduction (neurorestoration) and (iii) to supply a permissive environment to promote axonal sprouting (neuroregenerative therapies). Pre-clinical studies have raised hope in functional recovery through the antagonism of growth inhibitors, application of growth factors, cell transplantation, and vaccination strategies. To date, even though based on successful pre-clinical animal studies, results of clinical trials are characterized by dampened effects attributable to difficulties in the study design (patient heterogeneity) and species differences. A combination of complementary therapeutic strategies might be considered pre-requisite for future synergistic approaches. Here, we line out pre-clinical interventions resulting in improved functional neurological outcome after spinal cord injury and track them on their intended way to bedside.

Protective effects of extract of Ginkgo biloba (EGb 761) on nerve cells after spinal cord injury in rats

STUDY DESIGN

An experimental animal model was used to assess spinal cord injury following lateral hemitransection at thoracic spinal cord level.

OBJECTIVE

To determine whether extract of Ginkgo biloba (EGb) could have a neuroprotective effect in spinal cord injury (SCI) in rats.

SETTING

Department of Biological Sciences and Biotechnology, Tsinghua University, China.

METHODS

A total of 72 adult rats were divided randomly into three groups: the EGb group, normal saline (NS) group, and sham operation group (sham group). After thoracic spinal cord hemitransection was performed at the level of the 9th thoracic vertebra (T9), rats in the EGb group were given 100 mg/kg EGb 761 daily, while rats in the NS group received NS. The rats in the sham group only underwent laminectomy without spinal cord hemitransection. At various time points after surgery, thoracic spinal cords were sampled and sliced for histochemistry, immunohistochemistry of inducible nitric oxide synthase (iNOS), and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) of apoptotic cells.

RESULTS

Myelin staining showed that the area of cavities was small and the demyelinated zones were limited at and around the injury site of the spinal cord in the EGb group, while the area of cavities was large and the demyelinated zones were serious in the NS group. Nissl staining showed that the ratio of bilateral ventral horn neurons (transection side/uninjured side) in the EGb group was higher than that in the NS group (P<0.05). The apoptotic index and the percentage of iNOS-positive cells were lower in the EGb group than in the NS group. Furthermore, the percentage of iNOS-positive cells positively correlated with the apoptotic index (r( 2)=0.729, P<0.01) after SCI.

CONCLUSION

This study demonstrated that EGb 761 could inhibit iNOS expression and have neuroprotective effect by preventing nerve cells from apoptosis after SCI in rats.

Quercetin promotes functional recovery following acute spinal cord injury

We tested the hypothesis that quercetin, a potent Fe(2+)-chelating flavonoid, would decrease secondary damage following spinal cord trauma. MRI studies using the relaxation of the T1 proton signal caused by Fe(2+) ions and the dose-dependent reversal of this effect by addition of quercetin in aqueous solution were used to guide us to the dosage of quercetin to be used in animal experimentations. Forty-four male Wistar rats were used in two experimental series to test the hypothesis that administration of quercetin improves recovery of motor function after acute traumatic spinal cord injury. Animals were subjected to laminectomy and subjected to an extradural 40-g force clip compression for 5 sec at T7. Quercetin or saline was administered intraperitoneally 1 h after injury and then every 12 hr thereafter. Recovery of motor function was assessed using BBB scores at weekly intervals for 4 weeks. A dose of 2.5 micromoles quercetin/kg body weight did not result in significantly better functional outcome, whereas doses ranging from 5 to 100 micromoles quercetin/kg body weight resulted in a significantly better functional outcome with half or more of the animals walking, although with deficit; in contrast, no animals walked in the group of saline-treated animals. No significant differences in behavioral outcome were seen amongst the doses ranging from 5 to 100 micromol/kg, nor was there a difference if animals were treated for 4 or 10 days. Therapeutic outcome was coincident with more efficient iron clearance, suggesting that one possible mechanism whereby quercetin decreases secondary damage is through iron chelation.

Methylprednisolone in acute spinal cord injuries

BACKGROUND

Methylprednisolone is the only neuroprotective therapy advocated in acute non-penetrating spinal cord injury. Trials indicate improved neurological outcome following early administration of a high dose regime. The National Spinal Injuries Unit (NSIU) has promoted this regime by a simple laminated poster sent to all Irish A&E departments.

AIM

To assess the use of methylprednisolone in patients with spinal cord injuries.

METHODS

A retrospective audit of patient data for all patients admitted with traumatic neurological impairment over a 12-month period.

RESULTS

One hundred ninety-six patients were admitted during the study period, 28 (14%) received intravenous methylprednisolone of which six had clear records documenting compliance. One patient received both dexamethasone and methylprednisolone in high doses and three had incorrect bolus dosages administered. Six patients received methylprednisolone infusion longer than the protocol, while five patients were given infusions shorter than recommended. Three patients were admitted to the unit that could have received the steroid regime at the point of transfer.

CONCLUSIONS

There was poor documentation of prescription orders and timing of administration. Only six patients had clear documentation allowing confirmation of adherence to the protocol of the National Acute Spinal Cord Injury Study (NASCIS) III trial.